Metabolic regulation of the carbonyl stress pathway and methylglyoxal in Lyme disease and relapsing fever spirochetes.

Methylglyoxal-dependent carbonyl stress pathway is active in Lyme disease spirochetes and influences their infection dynamics, but is absent in relapsing fever Borrelia.

• Why it matters: Understanding how metabolic pathways affect bacterial survival and pathogenicity can reveal new targets for disease control, especially since this pathway's role in different Borrelia species was unclear.
• What they did: The study identified environmental signals activating carbonyl stress, demonstrated that methylglyoxal production depends on the mgsA gene, and compared its activity across Borrelia species using in vivo models.
• The result: Activation of this pathway in Lyme disease spirochetes modulates their lifestyle and reduces spirochetemia during infection, suggesting it plays a role in pathogen persistence and host interaction.